Related Field
This invention relates to gearboxes, for example for use in vehicle transmissions.
In both static machines and vehicles it can be desirable to transmit rotation from one or more drive sources to an output shaft. It is conventional to interpose a gearbox between the drive source and the output shaft to increase the range of speeds and/or torques available at the output shaft. The gearbox allows a user to select the gear ratio between the drive source and the output shaft.
Description of Related Art
In one type of gearbox drive is applied from a drive source to two intermediate shafts. Each intermediate shaft can be coupled to a common output shaft at a variety of gear ratios. By convention the gears are numbered in order, with first gear being the lowest gear. Normally, one of the intermediate shafts carries the odd gears and the other of the intermediate shafts carries the even gears. Typically two friction clutches are provided to allow each of the intermediate shafts to be driven independently and provide the ability to maintain drive torque during upshifts. One example of such a gearbox is disclosed in US 2012/0035013.
It would be desirable to maintain the quality of gear shifts in such gearboxes whilst improving the mechanical efficiency and reducing the size and weight of such gearboxes.